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TELEPHONE SYSTEM. I No. 289,539. E Patented Dec. 4, 1883.

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CHARLES ALMON JACKSON, OF LAWRENCE, MASSACHUSETTS, ASSIGNOR TO D. F. ROBINSON, OF SAME PLACE.

TELEPHONE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 289,539, dated December 4, 188 3.

Application filed September 17, 1883. (No model.)

To all whom it may concern.-

Be it known that I, CHARLES ALMON J ACK- SON, a citizen of the United States, residing at Lawrence, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Telephone Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled [o in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The object of this invention is, mainly, to avoid the loss of the time now consumed in waiting for an opportunity to call up any given 1 subscriber, as well as to do away with the central office, so called, now universally in use. In my present system I discard the central office, as before stated, and in lieu of the or dinary circuits, having their termini massed in such office,I employ a number of closed circuits sufficient to enable any subscriber, un- 2 5 der ordinary circumstances, to find some one of them unoccupied, or to greatly multiply the chances of his thus finding one, and I run the entire series of these wires through each subscribers instrument. Moreover, I furnish to 0 each subscriber an. adjustable or movable switch-board carrying a wire in which is included a receiver and transmitter and callbell or other signalinginstrument, and whose ends are connected with conductors secured to 3 5 such switch-board, these conductors being so arranged as to close the circuit through the wire when theline is broken, therebyenabling any subscriber to put himself in communication with and operate over any circuit-wire. By this means any subscriber is enabled to ascertain at once directly from his own instrument which of the circuit-wires are in use, and communicate directly with any other subscriber on any of said wires without recourse 4 5 to 'a central office. The conductors of the switch-board operate, when intercepting a key placed in each one of the circuit-wires, to break the circuit of such wire and reestablish such circuit through the wire carried by the switchboard. The wire thus becomes for the time a part of the circuit, and as it carries a receiver, transmitter, and call-bell, conversation may be had directly with any circuit not 00- cupied.

The drawings accompanying this specifica- 5 5 tion represent in Figure 1 a plan, in Fig. 2 a vertical cross-section, of a device embodying my improvements. Fig. 3 is an under side View of the movable switch-board.

In said drawings, Arcpresents atablet, upon the top of which are placed a number of telegraphic keys, B B B, &c., arranged in a straight row, and parallel to each other, the number of these keys being determined by the extent of business carried on in any particular locality or localities. In the present instance I have shown five keys, each of which is composed of two plate-springs, a b, of conducting metal, the free end of one (for instance, a) resting upon the free end of the other, b, as shown in Figs. 1 and 2.

O O G, &c., represent a series of telephonic circuit-wires, each wire being intercepted by a key, B, as shown. WVhen the two portions a b of a key are separated, the circuit through the wire 0 is broken, and vice versa.

D represents a switch-board disposed above the range of keys B B, &c., and supported upon horizontal parallel rods E E, in manner to slide upon the latter transversely of the said range of keys, said switch-board preferably carrying a pointer, F, to enable it to be readily adjusted in position over any given key.

Grepresents a conducting-wire, the two ends 8 5 c d of which pass down through the switchboard, and are connected, respectively, with two conductors, e f, in the form of knobs, secured to the under side of the switch-board, the end a being connected with the knob e 0 and the end cl with the knob f, as shown in Figs. 2 and 3 of the drawings, and in dotted lines in Fig. 1 Included in the wire G is a receiver, H, and transmitter I, as shown. The two knobs e f are so arranged with respect to 5 the keys B as when passing over any one of said keys to separate its two parts and break the circuit through the line-wire 0, connecting with such key, and re-establish such circuit through the wire G, carried by the switchboard, therebyputting the receiver and transmitter of such wire G in communication with the wire 0.

As shown in the accompanying drawings, the knob f extends below the knob e and operates with the lower portion, 1), of any key, while the knob e operates with the upper portion, a, of any key. When the switch-board is moved over any key, the knob e bears upon and opens connection with the portion a of such key, while the knob f bears upon and opens connection with the portion 1) of the key,

at the same time pushing down the latter and breaking the circuit through such key.

By this simple device, when a subscriber desires to communicate with another, he has only to move the switch from one key to another thereby for the time closing the circuit with some one line C, at the same time placing the receiverH to his ear, and is thus enabled to ascertain which wire 0 is unoccupied. 7 When an unoccupied wire 0 is found, the subscriber allows the switch-board to remain over such key, and can then communicate directly with any subscriber on said line through the transmitter I. As soon as the knobs ef pass by and release the key the latter automatically closes and the circuit is reestablished direct through the wire 0.

I have described myinvention as applied to a telephonic system which necessitates the discarding of a central office and the employment of additional circuit-wires. The principle of my invention, however, is applicable to the present system, in which a central office is used, as it will be only necessary in this latter system to mass the wires together at each subscribers instrument in the manner shown in the drawings, in which the wires 0 0, 8m. may be the wires of the present system.

I have adapted the switchboard and its adjuncts to operate with the two systems, whether in the same city or locality, or in two cities or localities more or less widely separated; but this adaptation is the subject of another application for a patent which I am about to file.

The wires 0 O, 850., represent ordinary telephonic circuits, and the call is made over them precisely as in any telephone.

I claim 1. The combination, with a series of telephonic closed circuit-wires massed together, with a circuit-breaking key to each, of a movable switch-board carrying a device for breaking the circuit through any one of such wires and re-establishing it through such switchboard.

2. A telephonic system embracing a series of telephonic linewires massed together, a circuit-breaking key interrupting each wire, a movable switch-board carrying a device for breaking the circuit through any wire at its key and re-establishing such circuit through such switch-board, and a receiver and transmitter carried by saidboard.

3. In combination, a series of telephonic closed circuit-wires massed together, each including a circuit-breaking key, a movable switch-board adapted to move from one to the other of such keys, a conducting-wire with its opposite ends secured to conductors carried by said board, which conductors operate to open the key and break the circuit thereat, and a receiver and transmitter included in the latter w1re.

4:. In combination, the wires 0, keys B, movable switch-board D, conductors e f, wire G, receiver II, and transmitter I, substantially as shown and described.

I11 testimony whereof I affix my signature in presence of two witnesses.

CHARLES ALMON J AOKSON \Vitnesses:

F. CURTIS, A. HAYDEN. 

